1. Field of the Invention
This invention relates to a process for making electro-optic elements and particularly liquid crystal display elements and liquid crystal-optical shutter arrays.
2. Description of the Prior Art
Recently, with growing demand for liquid crystal cells of larger size, higher quality, or more sophisticated functions, it has become desired to make uniform the thickness of liquid crystal cells as far as possible for improving characteristics thereof.
In order to achieve a given uniform cell thickness, there has been taken a measure which comprises dispersing glass fiber or fine glass beads with a definite diameter as an inner spacer in liquid crystal cells, thereby controlling the cell thickness depending upon the diameter of the fiber or beads.
However, this measure is unsatisfactory in the cases when liquid crystal cells are used as display parts of electronic devices such as desk or pocketsize calculators and wrist watches. They are desired to be thinner or lighter for the purpose of reducing the whole thickness or weight of the device. Therefore, electrode substrates of the cells are made of, for example, glass plates of 0.7 mm or less (preferably 0.5 mm) in thickness or plastic sheets of about 0.5 or about 0.4 mm in thickness. When a liquid crystal is sandwiched between a pair of such thin glass plates or plastic sheets, the electrode plates of the resulting liquid crystal display element are liable to undulate even when glass fiber or beads of a difinite diameter are distributed in the liquid crystal: in practice, no liquid crystal display cell of enough uniform thickness is obtained. It has been particulary difficult to uniform the cell thickness when thin glass plates or plastic sheets as mentioned above are used as electrode substrates for such large-sized liquid crystal display panels as requested for as display parts of personal computers and the like.
Nonuniform thickness of a liquid crystal layer due to the undulation or the like is undesirable for liquid crystal display elements, since this makes impossible the formation of a uniform monodomain.